There is substantial evidence that inadequate sleep contributes to health disparities that burden African Americans. Our recent data implicate the fear of losing vigilance to be an important contributor to compromised sleep in the lower socio-economic urban environments in which African Americans are disproportionately represented. Participants with PTSD had reduced slow wave sleep (SWS) and shorter continuous segments of rapid eye movement (REM) sleep. Some of the participants from stressed neighborhoods, however, do not report or exhibit curtailed or disturbed sleep. The purpose of the proposed research is to obtain ecologically valid assessments of the sleep disruptive effects of a stressful neighborhood environment, and determine what contributes resilience versus vulnerability to these effects. We will identify good and poor sleepers living in high crime urban areas. We will incorporate evaluation of the contributions of genotypes previously implicated in sleep tendencies or response to experimental sleep manipulations into models that will also consider life style, trauma exposure, and PTSD. We will monitor pre-sleep behaviors and cognitions and determine how in-home sleep relates to measures obtained in a laboratory setting and contribute to functional outcomes. Insights from this study will inform individual and public healt approaches to ameliorating health disparities attributable to compromised sleep.